Honing stone assembly



June 5, 1962 c. STELMACHOWSKI 3,037,333

HONING STONE ASSEMBLY Filed Dec. 7, 1959 2 Sheets-Sheet 1 CARL STELMACHOWSK! A'r'rY.

[NVENTOR June 5, 1962 c. STELMACHOWSKI 3,037,333

HONING STONE ASSEMBLY Filed Dec. 7, 1959 2 Sheets'Sheet 2 w 5 F f fi ?'IIIIIIIIIIAT Iuvamo CARL STELMACHOW 3,037,333 HONING STONE ASSEMBLY Carl Stelmachowski, Chicago, Ill., assignor to Super-Cut, Inc., Chicago, 111., a corporation of Illinois Filed Dec. 7, 1959, Ser. No. 857,800 1 Claim. (Cl. 51-1845) The present invention relates to honing apparatus and more particularly to cylinder surfacing hones of the type which are designed for use in surfacing the cylindrical walls or bores of small workpieces such as, for example, the bores of connecting rods, gears and the like, as well as small diameter cylindrical surfaces associated with a wide variety of engine or machine tool parts.

The invention is particularly concerned with honing or abrading elements for such honing apparatus in which the honing stone or abrasive element proper is mounted and supported in a nonabrasive backing member so that as the stone wears the encasing portion of the backing member likewise will Wear so that the stone may be worn to completion. Abrading elements of this general character as used in honing tools generally comprise an elongated bar of bonded abrasive known as a stick, together with a carrier by means of which the stick is laterally supported or backed, with the stick and carrier assembly being loosely mounted in an expansible honing arbor. Briefly, the environment [for abrasive elements of this sort comprises a spindle which is drivingly connected at its inner end to a machine head which is capable of imparting combined rotational and reciprocating motion to the spindle. 7 At its lower end, the spindle is provided with an abrading head or arbor having a single or a plurality of circumferentially arranged spaced slots therein, each slot being adapted to loosely receive therein one of the abrasive elements. These elements are adapted to be moved radially outwardly or expanded against the cylindrical surface of the workpiece by a cone or wedge member attached to a shaft extending through the spindle bore and axially shiftable in the bore by conventional hydraulic mechanism common to a wide variety of such honing machines. With the abrasive elements thus expanded outwardly against the inside surface of the workpiece and with reciprocating movements being applied to the spindle, rapid removal of stock from the cylindrical surface undergoing honing will result.

The present invention is designed to overcome certain limitations that are attendant upon the construction and use of honing machines which are specifically designed for small diameter work such as the honing of gears, connecting rod bores, small bore engine cylinders and the bores of small sleeves and similar special parts. Where such small diameter cylindrical surfaces are concerned, no practical way has been found to maintain the abrasive elements captured Within the slots provided in the abrading head or arbor and these abrasive elements are allowed complete freedom of floating movement within the slots so that when a rotating arbor is withdrawn from the cylindrical bore of the workpiece, there is a tendency for the abrasive elements to fly outwardly under the influence of centrifugal forces and become disassociated from the machine. Loss of abrasive elements from such a cause is frequent and where the abrasive stick or element proper is in the form of a diamond-impregnated matrix, such losses are serious, to say nothing of the loss of time involved in searching for such far flung honing elements.

United States Patent Instances have been recorded where damage to the person has resulted from these flying objects as well as property damage both to the elements and to adjacent machinery or fixtures. This problem of loss of abrasive elements does not exist in connection with the larger size arbors designed for honing large diameter workpieces such as the cylinder Walls of large bore combustion engines, steam engines and the like since in such instances the problem has been solved by the provision of garter springs and similar retention devices for which there is ample room.

In conventional honing machines the abrasive elements or sticks are frequently carried in metal jaws with the stick being cemented in place within the jaws. Such abrasive assemblies do not allow the abrasive stick to be worn to completion inasmuch as after the stick has be come worn to the point where the metal backing jawv engages the workpiece, the unit, together with the only partially worn stick, must be discarded.

The present invention is designed to overcome both of the above-noted limitations that are attendant upon the construction and use of conventional honing machine and, toward this end, it contemplates first, the provision of a novel form of abrading element or assembly which, in combination with the arbor in which it is mounted for radial expansion, afiords an effective detent locking means whereby the assembly will be retained within its respective slot against dislodgment under the influence of centrifugal forces when the arbor is rotating freely with the workpiece withdrawn therefrom. Secondly, the invention contemplates the provision of a honing element wherein the carrier or backing element is of lesshardness than that of the abrasive material of the abrasive stick. The carrier may thus be formed of a suitable moldable material such as a phenolic resinous condensation product which, as the stick wears, will likewise wear, whereby the stick may be worn to completion. In the case of diamond abrasive, the carrier may be formed of steel.

The provision of an abrasive element or assembly of the character briefly outlined above being among the principal objects of the present invention, numerous other objects and advantages will become apparent as the following description ensues.

In the accompanying two sheets of drawings forming a part of this specification a preferred embodiment of the invention has been illustrated.

In these drawings:

FIG. 1 is a side elevational view, partly in section, of a honing machine arbor showing a plurality of abrasive elements constructed in accordance with the principles of the present invention ,operatively applied thereto;

FIG. 2 is an enlarged perspective view of one of the abrasive elements of the present invention;

FIG. 3 is a plan view of the element shown in FIG. 2;

FIG. 4 is a side elevation-a1 view of, the element of FIG. 2; i

FIG. 5 is an end view of the element of FIG. 2;

FIG. 6 is a further enlarged sectional view taken substantially along the line 66 of FIG. 3;

FIG. 7 is a similar enlarged sectional view taken substantiall-y along the line 77 of FIG. 4; and

FIG. 8 is a sectional view taken substantially along the line 8-8 of FIG. 4. I

Referring now to the drawings in detail and in particular to FIG. 1, there is illustrated a honing head 10 which is adapted to be attached to its proximate or inner driven end to a conventional honing machine spindle (not shown). The honing head may extend either vertically, horizontally, or at an angle such as 45 for example, depending upon the type of honing machine with which it is to be used. In the present illustrated form of the head, the axis of rotation is horizontal merely for purposes of illustration.

The honing head 10, with but one single constructional detail which will be pointed out subsequently, is of conventional design and it is illustrative of but one specific form of a wide variety of honing heads which are capable of receiving the novel abrasive element of the present invention. The particular head 10 selected for illustration herein involves in its general organization an arbor 12 having a plurality of slots 14 each of which is designed for reception wherein a wedge element 16 having a tapered working face 17 and having a hook 18 or other shoulderforming means whereby the wedge element may be slid longitudinally or reciprocated within the slot 14 for expanding one of the abrasive elements of the present invention radially in a manner that will be set forth presently.

Telescopically mounted relative to the arbor 12 is a sleeve-like holder 20 having adjacent its distal end a plurality of equally and circumferentially spaced slots 22 therethrough. The slots 22 are of elongated design and have their longitudinal axes extending lengthwise of the holder. The width of the slots 22 is commensurate with the width of a series of abrasive elements or assemblies 30 (FIG. 2) which are designed for reception in the slots.

As previously stated, the honing head described above may be purely of conventional construction, although, if desired, it may differ from conventional heads by the provision of a pair of retention lips or shoulders 32 and 34 at the ends of the slots 22 and near the mouth thereof, such lips being designed for cooperation with certain detent means associated with the various abrasive elements 30 for retaining the latter in position within the slots against dislodgement.

Referring now additionally to FIGS. 2 to 8 inclusive, each abrasive element or assembly 30 comprises an abrasive honing stone or stick 4t} and a combined non-abrasive backing member and shoe 42 formed of a material which is of less hardness than that of the abrasive material of the stick 40. The honing stone 40 is of elongated construction and is substantially rectangular in transverse cross section. It is provided with a working face 44 and practically all but this working face is embedded in the material of the backing member 42. At the opposite ends thereof the working face 44 is relieved as at 46 to provide slight bevels or inclined faces. A shallow groove 47 extends longitudinally and centrally along the working face 44 for passage therealong of a suitable coolant which is customarily employed in connection with honing operations.

The side faces 48 and 50 of the backing member 42 are planar and parallel and they extend at a right angle to the general plane of the working face. The bottom face 52 of the backing member 42 is inclined at a small angle of approximately 10 to the general plane of the working face 44 although the specific angle involved is not critical. The end faces 54 and 56 are curved and extend at a right angle to the plane of the working face 44.

It is to be noted that the longitudinal extent of the backing member 42 is greater than that of the abrasive hone 40 so that there are provided, in effect, a pair of thick longitudinally extending tabs 57 at the opposite ends respectively of the hone. These tabs have outer faces which are designed to wear uniformly with the working face of the hone during actual honing operations.

Referring now specifically to FIGS. 6, 7 and 8, one end of the backing member 42 is formed with a cylindrical socket 60 therein and within this socket there is disposed a small cylindrical retainer cage or cup 62 having a bottom wall 64 seated on the bottom face 66 of the socket 66 and having an open outer end or rim 68 which is beaded inwardly to produce a rim opening of slightly less diameter than the diameter of a detent ball 70 which is loosely received within a cup 62. The detent ball 70 seats upon the outer annular face of an O-ring 72 which, in turn, is seated upon the bottom face 66 of the cup and which atfords the necessary degree of resilience to maintain the detent ball 70 yieldingly in position against the inturned rim 68. The O-n'ng 70 may be formed of a suitable resilient elastomeric material such as rubber, either natural or synthetic, or a rubber substitute.

The depth of the socket 60, the longitudinal extent of the cup 62, the diameter of the rim opening 68 and the diameter of the detent ball 70 are so designed that the surface of the ball projects a slight distance beyond the end face 56 of the backing member 42 for detent purposes. The cup 62 and its contained detent ball 70 and O-ring 72 may be embedded in the material of the backing member 42 during the molding operation by means of which the member 42 and honing stone 40 are assembled.

In the use of the honing elements 30 in a honing operation, these elements may be easily inserted into the respective slots 22 in the holder 20 by the simple expedient of first inserting or hooking, so to speak, the end 54 of the backing member 42 beneath the lip 32 of the slot within which it is to be installed, after which the element may be pushed inwardly so that the detent ball 70 will snap behind the other lip 34 and thus the element 30 as a whole will be loosely disposed within the slot. The inclined bottom face 52 will move into register with the similarly inclined working face 17 of the adjacent wedge element 16 so as to limit the inward movement of the backing member while the lips 32 and 34 Will retain the abrasive element 30 within the slot against dislodgement under the influence of centrifugal forces when the rotating arbor 12 is withdrawn from the workpiece. Where the slots 22 of the holder are not formed with the lips 32 and 34, the honing elements 30 may simply be pushed into position where frictional forces will hold them in place.

It is to be distinctly understood that the honing head 10 illustrated herein is purely exemplary of one particular form of head adaptable for use in connection with abrading elements or assemblies constructed according to the present invention and that a large variety of other honing heads having slotted-arbors, holders or other members having abrasive elements-confining slots therein may with but slight modification be adapted for use in receiving the abrasive elements of the present invention. Many honing heads currently in use which, instead of employing individual wedge elements such as having been shown at 16 herein, employ a single wedge member common to all of the abrasive elements for forcing the same radially outwardly simultaneously. Irrespective however of the particular environment with which the abrasive elements of the present invention may be associated, the essential features of the invention are at all times preserved.

It is to be understood that the invention is not to be limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings or described in this specification since the invention is capable of other embodiments and of being practiced in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, only insofar as the invention has particularly been pointed out in the accompanying claim is the same to be limited.

Having thus described the invention What I claim as new and desire to secure by Letters Patent is:

A honing element for a honing head having a body provided with slots for the reception of a number of such elements, and a wedge member for moving said elements radially outwardly in the slots, said honing element including an abrasive stone of appreciable length relative to its width and thickness, and a backing member formed of non-abrasive material of less hardness than the hardness of the abrasive stone and within which the stone is partially embedded, said backing member covering said stone on substantially all surfaces except the working surface thereof, the longitudinal extent of said backing member being greater than that of the stone to provide a pair of longitudinally extending tabs at the opposite ends of the honing element respectively, said tabs having surfaces adapted to wear uniformly in the general am of the working, face of the stone, one of said tabs being formed with a socket in its outer end face, a generally cylindrical cup-shaped retainer substantially embedded in said socket, said retainer having a cylindrical wall presenting an inturned open rim, a detent ball within said retainer, and a resilient O-ring formed of elastomeric material seated on the bottom wall of said socket,

said ball being nested within the O-ring, making circular line contact therewith, and being compressed between the O-ring and said open rim.

References Cited in the file of this patent UNITED STATES PATENTS 1,601,813 Emerson Oct. 5, 1926 2,419,297 Steigerwald Apr. 22, 1947 2,467,094 Peden Apr. 12, 1949 2,550,795 Flaton May 1, 1951 2,675,654 Harris Apr. 20, 1954 2,823,498 Saunders Feb. 18, 1958 2,952,952 Stanhope Sept. 20, 1960 FOREIGN PATENTS 766,199 France Apr. 9, 1934 

